Abstract
The Add-my-Pet (AmP) collection of data on energetics and Dynamic Energy
Budget (DEB) parameters currently contains 92 species of turtles and 23
species of crocodiles. We discuss patterns of eco-physiological traits
of turtles and crocodiles, as functions of parameter values, and compare
them with other taxa. Turtles and crocodiles accurately match the
general rule that the life-time cumulated neonate mass production equals
ultimate weight. The weight at birth for reptiles scales with ultimate
weight to the power 0.6. The scaling exponent is between that of
amphibians and birds, while that for mammals is close to 1. We explain
why this points to limitations imposed by embryonic respiration, the
role of water stress and the accumulation of nitrogen waste during the
embryo stage. Weight at puberty is proportional to ultimate weight, and
is the largest for crocodiles, followed by that of turtles. These facts
explain why the precociality coefficient – approximated by the ratio of
weight at birth and weight at puberty at abundant food – decreases with
ultimate weight. It is the smallest for crocodile,s because of their
large size, while that lizards and snakes are much larger than for
turtles. The maximum reserve capacity in both turtles and crocodiles
clearly decreases with the precociality coefficient. This relationship
has not be found that clearly in other taxa, not even in other reptiles.
Crocodiles have a relatively large assimilation rate and, as
consequence, a large reserve capacity. Sea-turtles have a small weight
and age at birth, which we link to reducing risks on the beach.